Influenza has killed more people around the world than any other illness. Although healthcare today is better than ever, the risk of harm to the individual or a serious pandemic remains, which is why getting the annual flu jab is essential.

It’s not always as effective as one would hope, though: It’s designed to protect against a rapidly evolving group of viruses, and the vaccine needs to constantly be updated and dished out. A new Scientific Reports study, however, may have a solution: a one-time shot that gives you lifelong protection from most strains of the virus.

A team led by the Nebraska Center for Virology (NCV) have developed an unconventional inoculation, one that goes back to basics, in a manner of speaking.

Influenza comes in several different genera, or “types”, all of which behave differently. Things weren’t always this way though; each strain has evolved from a more primitive progenitor. This means that each strain still shares a key set of genes from their last common ancestor.

The team from NCV looked back over the evolutionary history of the H1, H2, H3, and H5 influenza strains. After successfully identifying the ancestral genes that they all share, they synthesized them in a laboratory setting.

Afterwards, they used these genes to engineer a new flu vaccine, and tested it out on mice. Those that were given this novel shot survived being exposed to lethal doses over seven of nine influenza viruses; additionally, those that were given more potent versions of the vaccines didn’t even fall ill during exposure.

In contrast, mice given conventional influenza vaccines all got sick and perished when exposed to the very same viruses. Although it’s not yet clear if the mice that survived now have lifelong immunity, it’s a fair bet to make.